FIGURE 2.

Synthesis and secretion of human apoB:1000 are dependent on PLTP activity. Primary cultures of hepatocytes isolated from wild type (A) and PLTP knock-out (B) mice were transfected with pLNCB:1000 or empty pLNCX and metabolically labeled with [³⁵S]Met/Cys as described under “Experimental Procedures.” Secreted and cellular ³⁵S-labeled human apoB:1000 was immunoprecipitated using antibody to human apoB100 and processed as described in the text. A, autoradiogram of ³⁵S-labeled human apoB:1000 expressed in wild type hepatocytes (lane 3), untransfected cells (lane 1), and cells transfected with empty pLNCX (lane 2). B, autoradiogram of ³⁵S-labeled apoB:1000 synthesized and secreted by PLTP-KO hepatocytes (lanes 1 and 2).